Ear, nose, and throat (ENT) surgeons—have been
using minimally invasive surgery to treat ENT problems for many years, long before the term became popular. Head and neck disorders are well suited for minimally invasive diagnostic and surgical approaches because the nasal, ear, and throat passages offer a natural entryway for the sophisticated, thin instruments used in these procedures. These types of procedures result in less tissue damage, a faster recovery, less pain, and less scarring than treatments performed through open incisions. For ENT minimally invasive procedures, that require external incisions, the scarring is kept to a minimum. Surgery in the head and neck presents a unique challenge because of cosmetic considerations related to skin incisions on and around the face. Fibreoptic endoscopes, telescopes, surgical microscopes and lasers allow many diagnostic and therapeutic procedures in the head and neck to be performed, without a skin incision, through the ear, nose and mouth.
The earliest rhinoscopy tool, dating to 12th century, is the nasal speculum. Nasal specula vary in design from a conical shaped metal insert to a two-pronged spreader. Specula for anterior rhinoscopy widen the nasal openings for viewing while at the same time making room for other examining instruments. A strong light source is required in order for any speculum to be of use. Prior to invention of the light bulb, patients were awkwardly situated by a window or candle so the doctor could see into the nasal cavity. A patient’s head would be tilted back with the tip of their nose forcibly raised by a thumb or speculum.
In the 17th century, Pierre Borel designed a concave mirror to help pass sunlight into the nasal cavity. Borel’s design was later modified by perforating the centre of the mirror and attaching it to a headband. Light from a window or candle was thus reflected into the nasal cavity, and the doctor was able to have a direct, well-lit view through the perforation. Also, by placing the mirror on a headband the doctor had a free hand for other purposes.
Intubation tubes started replacing tracheotomy by 1891, and now of course forms the mainstay of treatment for critical patients. All general anaesthesia depends significantly on endotracheal intubation and surgery is better as a result of safer anaesthesia techniques.
In 1904, Chevalier Jackson designed his bronchoscope, and used endoscopes through the mouth, to remove foreign bodies from the bronchus as well as the oesophagus.
Ear surgery has always been done through minimally invasive techniques and it improved leaps and bounds after the introduction of the operating microscope about 60 years ago.
Nasal and sinus surgery benefited tremendously with the advent of nasal endoscopes about 40 years ago, but was popularized only in the last 25 years.
Fibreoptic endoscopes for the larynx, bronchus and oesophagus have made surgery of the aero-digestive tracts a lot safer and easier.
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Some ear surgery can be done using an endomeatal approach which involves no visible incision. Occasionally endaural or postaural incisions are required for better exposure or to harvest temporalis fascia. Both are small incisions and extremely cosmetic.
The development of endoscopic sinus surgery has enabled surgeons to visualize the sinus openings, remove diseased tissue, and make the natural sinus openings larger directly, all by working through the nostrils. With the addition of techniques and new instrumentation, rarely is it necessary to make an incision on the face or in the upper gum to gain access to the diseased sinus.
The throat naturally provides easy access for surgery and most oral and pharyngeal surgery can be done trans-orally. In the larynx, use of the laryngoscope with the operating microscope and lasers has meant that external incisions are required only very rarely. Endoscopes, lasers and newer instrumentation have also made most surgery in the aero-digestive tract possible without external incisions.
All ENT surgery, other than radical tumour surgery, uses minimally invasive procedures.
In the ear, with the use of the microscope, many surgeries can be done endomeatally, i.e. through the external ear canal. These operations include myringotomy with grommet insertion, myringoplasty, stapectomy and ossiculoplasty. Tympanoplasty is usually done with a small endaural incision which requires a tiny external incision in the incisura, or a cosmetic post-aural incision. In patients with a wide external canal, tympanoplasty can however, be done endomeatally using tragal perichondrium for tympanic membrane reconstruction. For mastoidectomy, it is usual to use an endaural or postaural incision as greater exposure is required.
The nose is uniquely situated and suited for minimally invasive surgical approaches. The nasal passages allow for surgical access to the sinuses, the eyes, and even parts of the brain, without the need for a skin incision. It is now possible to operate on the sinuses entirely through the nostril and achieve better clearance of disease and hence, better results using an endoscope. Only in few cases where there is considerable bone involvement as in malignancy or invasive fungus, is an external or labial incision required. Operations done endoscopically include surgery for chronic sinusitis, nasal polyposis, benign and restricted malignant tumours, epistaxis, fungal sinusitis and other granulomas. Orbit surgery done trans-nasally includes Endoscopic DCR, orbital decompression, removal of orbital abscesses or tumours and optic nerve decompression. Surgery of the skullbase done includes endoscopic repair of CSF rhinorrhoea, pituitary surgery and other tumours of the skullbase. These surgeries often require trans-cranial procedures with increased morbidity, complications and prolonged hospital stay.
In the larynx, the aim is to rid the patient of the disease or tumour, and to preserve the principal functions of the larynx, which are voice, swallowing and comfortable breathing without a tracheotomy tube. If there is a small part of the larynx involved with the cancer, a partial laryngectomy can be performed. This may either be performed through an endoscopic laser technique or through an open procedure. Endoscopic procedures are done through the mouth without an external incision or tracheostomy. In most cases, the patient is able to go home the next day. This approach is particularly advantageous in reducing the pain or morbidity of open surgery of the larynx. In some situations, laryngectomy may need to be done externally
Minimally invasive solutions are preferred whenever possible, allowing less tissue damage and faster recovery time. There are dramatic benefits to minimally invasive surgery. Prolonged hospital stays can be avoided if minimally invasive endoscopic or microscopic approaches are used. Patients also enjoy reduced post-operative pain and less scarring than open surgery.
Traditionally ear surgery has been done using post-aural incisions, which uses an external incision but still gives a cosmetic scar. In the nose, trans-facial and sublabial approaches have almost completely been replaced by endoscopic procedures. Neck incisions are still required for most neck surgery though some surgeons have attempted endoscopic neck surgery for benign neck masses.
The techniques of minimally invasive surgery are here to stay, and future improvements in cameras, endoscopes, monitors, instruments and surgeon skills should see a further blossoming of these procedures allowing them to replace most surgeries that require large external approaches. Image-Guided Surgery with the help of a revolutionary imaging tool that allows CT guided surgery enables us to build a three-dimensional picture of the patient’s anatomy allowing for more complete removal of disease and fewer complications. Such advances, including intra-operative MRI will see the face of surgery changing dramatically in the near future.